Flask



FIG. 1 is a front view showing the new design for the flask;

FIG. 2 is a back view of the flask in FIG. 1;

FIG. 3 is a left side view of the flask in FIG. 1;

FIG. 4 is a right side view of the flask in FIG. 1;

FIG. 5 is a top view of the flask in FIG. 1;

FIG. 6 is a bottom view of the flask in FIG. 1; and,

FIG. 7 is a perspective view of the flask in FIG. 1. 

CLAIM The ornamental design for a flask, as shown and described. 